Investigational AKT Inhibitor in Triple-Negative Breast Cancer
When added to paclitaxel in the first-line treatment of metastatic triple-negative breast cancer, the AKT inhibitor ipatasertib improves progression-free survival and warrants further investigation, according to the results of the LOTUS trial. Sung-Bae Kim, MD, of the University of Ulsan College of Medicine, Seoul, South Korea, and colleagues claimed these may be the first results supporting AKT-targeted therapy for this type of breast cancer. They published their multicenter phase II findings with this oral agent in The Lancet Oncology.
A total of 124 patients with unresectable locally advanced or metastatic disease were randomly assigned for treatment with either paclitaxel plus ipatasertib (62) or paclitaxel plus placebo (62). With a median follow-up of just over 10 months in both groups, median progression-free survival was longer with ipatasertib than without it in the intention-to-treat population (6.2 vs. 4.9 months). And the same was true among the 48 patients who had PTEN-low tumors, with progression-free survival of 6.2 months with ipatasertib and 3.7 months without it.
As for toxicity, patients treated with ipatasertib experienced grade ≥ 3 diarrhea, neutropenia, and decreased neutrophil count more often than those who did not (23% vs. 0%; 10% vs. 2%; and 8% vs. 6%, respectively). No patients in the ipatasertib group reported experiencing colitis.